1. Technical Field
The present invention relates to a speaker device, and relates to an improvement of the speaker device suitably used for an earphone device such as an earphone or a headphone, etc., for example, which is worn in an ear of a user.
2. Description of Related Art
Conventionally, for example a structure shown in FIG. 6 is known as the earphone device worn in the ear of the user. In this structure, one of the end faces of a cylindrical magnet 5 is fixed to an inside of a cup-shaped yoke 3 disposed in a case body 1; a thin vibrating film 7 is fixed to a tip of the yoke 3 to thereby cover an opening part of the yoke 3; the vibrating film 7 and the other end face of the magnet 5 are disposed to face each other; and a cylindrical coil 9 fixed to the vibrating film 7, is inserted into an outer periphery of the magnet 5, with a slight space provided between them.
In FIG. 6, the case body 1 is composed of a funnel-shaped base part 1a and a front cover 1b covering a top end (right side in the figure) of the base part 1a. The yoke 3 is supported in the case body 1 by fixing the top end of the opening part to the inside of the front cover 1b. 
Reference number 11 in FIG. 6 indicates a plurality of sound holes formed on a front cover 1b in penetrating manners on a front face of the vibrating film 7, and reference number 13 indicates a cable led out to outside. The cable 13 has a knot 13a in the base part 1a. are formed in penetrating manners at sites corresponding to
In this earphone device, a driving unit 15 for vibrating the vibrating film 7 is formed by the magnet 5 and the coil 9, and a voice signal is applied to the coil 9 from outside through the cable 13, so that the vibrating film 7 is vibrated by an operation of the driving unit 15 to thereby emit a sound, and the emitted sound is transmitted to the outside from the sound holes 11 on the front face of the vibrating film 47.
Then, such a kind of earphone device is formed into an external auditory canal inserting type and is put to practical use as a product actually.
The structure of the external auditory canal inserting type earphone device as shown in FIG. 7, is obtained by slightly modifying the structure of FIG. 6 for example, and the earphone device with this structure is used in such a way that the case body 1 is inserted into a cavity of concha 23 surrounded by tragus 17, antitragus 19, and concha 21 of a user so that the vibrating film 7 is approached to the cavity of concha 21, and a sound transmitting cylindrical body 27 protruded from the case body 1, is inserted into an external auditory canal 25 which extends to an eardrum (not shown) from the cavity of concha 23.
A coaxial shape (see FIG. 7) with a central axis of the vibrating film 7 and a central axis of the sound transmitting cylindrical body 27 aligned to each other, and a non-coaxial shape (see FIG. 8) with the central axis of the sound transmitting cylindrical body 27 set obliquely to the central axis of the vibrating film 7, can be given as actual products. FIG. 7 and FIG. 8 show a state that the earphone device is worn on a left ear.
Note that reference number 29 in FIG. 7 and FIG. 8 indicates a flexible ear chip (ear pat, ear piece) fit to an outer periphery of the sound transmitting cylindrical body 27, which is elastically abutted on an inner wall of the external auditory canal 25.
Incidentally, Japanese Patent Laid Open Publication No. 2010-283643 (patent document 1) discloses the earphone device as a publicly-known example.